Alkynes take alkanes to the next level…all the way up to a triple bond. Just like the "triple-dog dare" is the most intense level of dares, the triple bond is the most intense carbon-carbon bond because they involve six bonding electrons instead of the usual two (or four, in the case of alkenes).
Alkynes follow the formula CnH2n-2.
Alkynes follow the same naming rules as alkenes, making the bad boy above respond to the name 2-pentyne (the 2 indicates that the triple bond comes after the second carbon).
Want to take a stab at naming this one?
There are four carbons and one triple bond (on the first carbon), making this lovely lady respond to butyne.
Like all siblings, Alkynes copy what their big brother Alkenes do.
Specifically, the copy-cat Alkynes participate in hydrogenation and halogenations reactions, but they require two rounds of reactions: one to bring the triple bond to a double bond, and one to turn the double bond to a single bond. The first round will turn the alkyne to an alkene, and this might be where the reaction (and the copy-cat behavior) stops. If the reaction keeps going, the alkene can continue be transformed into an alkane.
Lets get ready to rumble. Round 1 of Alkyne halogenation:
And Round 2:
Oom-pah! Here's a song about Alkanes, Alkenes, and Alkynes (and, luckily, lyrics located in the description).